Here's the straight skinny on one of the "empty" messages (messages with what look like good headers, but with no message body). I can't tell if this is a "sample of one" or if it accurately reflects the normal situation when such "messages" are received. However, it is one data point.

On the ISP:
I have LMOS enabled for this account.
There are 2 messages on the ISP that are obviously virus or bad spam. However, Poco/McAfee combo will not download them. This may be the source of the empty email -- that is, there's a message on the ISP, but for some reason it can't get through. Note: I recognize a problem with this idea, in that there are two such messages on the ISP, but only one "empty" message in Poco's In box.
Screen shot using ISP web mail[Edit] Fixed url to screen shot [/Edit]

What shows in the message preview: Basically, the message preview (with "all headers" turned on) accurately shows the same data as contained in the MBX file. For those who want to see, here is a composit screen capture of what I see. (I've deleted most of the timeout messages. The red text should say "Some time protections not shown to keep graphic small.")

SWAG: This looks like some kind of race condition between Poco and McAfee. Poco thinks there's a message, because McAfee told it there was one, but McAfee does not finish processing the message before Poco decides to give up. Then, rather than throwing everything away, Poco inserts the "empty" email into its data structures.

Last edited by frazmi on Tue Jul 27, 2004 3:37 am, edited 1 time in total.

I've reinstalled McAfee twice with no error messages. The "missing component" is the Spam module, as far as I can tell -- which I chose not to install in order to use Poco's. I've been on the horn with McAfee tech support, and they tell me the AV is properly installed (as far as they can tell).

Also, 99% of messages come in OK. It's just a very few messages that have this problem. So I think the AV installation is OK.

I agree that this looks like McAfee is either deleting the message body or not downloading it in the first place. In the previous incarnation of the Poco Forum, there were many discussions about "blank" and "empty" mesages (not the same thing -- two different problems).

My post is intended to provide some solid data on the possible cause of the "empty" message problem -- at least, for one such message.

Ideally, it would be nice if Poco detected this kind of situation and did not insert the message in the Poco database. I don't see how a message that's "From <>" can possibly be considered valid.

Since you have speculated on the "race condition" between AV and PM, what happens if you increase the PM timeout?

That's a good idea... Timeout was set to 120 seconds. I've bumped it to 240 seconds.

Also, I've noticed that Poco-McAfee sometimes gets into a lo-o-o-o-o-o-o-ng download of tiny messages (I'm talking 30 minutes for 40KB message on VDSL). So far, these all seem to be virus-infected. I have not yet confirmed that there's a correlation with the "empty" messages -- but I suspect there is.

And then Jose said...

Please, could you check it after disabling that option?

I would love to, but I can't find any way to turn off timeout protection with McAfee. (I didn't use that with Norton, by the way.) If anybody knows how to kill TP with McAfee, please post. In the meantime, I'll try their tech support.

And finally, what about my "assertion" that messages with empty "from" headers should never be inserted into the message database. Anybody see any problem with that?